H/sub 2/ and NO/sub 2/ gas sensors with ZnO nanobelt layer on 36/spl deg/ LiTaO/sub 3/ and 64/spl deg/ LiNbO/sub 3/ SAW transducers

Single crystal nanobelts of ZnO were synthesized and deposited onto 36/spl deg/ YX LiTaO/sub 3/ and 64/spl deg/ YX LiNbO/sub 3/ surface acoustic wave (SAW) devices for gas sensing applications. Sensor response, defined as the change in resonant frequency, was measured for H/sub 2/ and NO/sub 2/ between 20 and 200/spl deg/C. Measured sensor responses were 3.5 kHz towards 10 ppm NO/sub 2/ for a 64/spl deg/ LiNbO/sub 3/ SAW transducer operating at 160/spl deg/C and 3 kHz towards 1% H/sub 2/ for a 36/spl deg/ LiTaO/sub 3/ SAW transducer operating at 185/spl deg/C temperature.